Adam,
I use Microsoft's Streets and Trips software on my laptop and I find it very user friendly. Using the View Menu, select Map fonts and enlarge the print on the map. I have a Jotto Desk installed on my dash and my laptop's 15 inch screen provides a nice moving map with the route highlighted in green.
The GPS plugs right into the laptop and we are good to go.
I always select PREFERRED ROADS and the software routes me thru using interstates and federal (US) highways. All of this type of software should be used in conjunction with other aids to navigation (atlas, etc.) not stand alone. I have also found that zooming in tight will give a good indication of the width of the road. Like anything else there is a learning curve; it is part of the fun of motorcoach travel!
Tuga & Karen Gaidry
2012 Honda Pilot